Asphalt concrete production has typically been conducted at permanent locations or facilities. These permanent locations or facilities require transport of the high temperature asphalt concrete from the production plant to installation locations which can be significant distances from the plant. Transportation of high temperature asphalt concrete over the open road produces significant problems in production, logistics and installation of the asphalt concrete. These difficulties include loss of heat, increased requirement of heat for transportation time periods, multiple trips to transport various asphalt concrete recipes necessary for roadway surfaces, as well as many other known issues.
Other issues in regards to permanent or fixed location asphalt concrete production facilities include heightened costs for small jobs requiring smaller volumes and multiple trips for differing grades of asphalt concrete. As a result, in small paving projects, a single grade of asphalt concrete will be delivered and utilized for the entire project as opposed to appropriate multi-layer asphalt concrete typically utilized when building roadway surfaces.
In building roadway surfaces, a base course must be first laid which normally requires larger aggregate having certain desirable properties. This larger aggregate in the base course can be three-quarter inch aggregate base in order to create the base course pavement utilized in the sublayer material of an asphalt roadway.
On top of the base course may be placed a wearing surface which utilizes finer quality of rock and aggregate, possibly in the range of one-quarter to one-half inch aggregate or less. Combinations of both the base course and the wearing surface thus increase the life of the asphalt roadway.
It has been proposed to provide a mobile asphalt production machine which may mix bituminous concrete at the job site utilizing an auger mixing mechanism. However these asphalt mixing machines have known production problems in making the various asphalt concrete recipes. Such drawbacks include the inability to create multiple grades of asphalt concrete while also not allowing for corresponding variations in the size of aggregate during the production process. These deficiencies make prior art asphalt production machines ineffective and inappropriate for mobile use to create varying asphalt concrete recipes which require the use of different sizes of fines, aggregate and other elements. It would thus be desirable to be able to produce multiple grades of asphalt concrete on location and on a mobile platform without the necessity of transporting the various grades of asphalt concrete from a permanent or fixed location production facility.
Thus, there is a need in the art to provide an asphalt concrete production machine which is both mobile and which accommodates recipe changes for various asphalt concrete quality and recipes thereby requiring different constituent ingredients. This need in the art is necessary to overcome one or more of the drawbacks associated with the asphalt concrete production machines known in the art.